U.S. patent number 10,104,591 [Application Number 15/892,964] was granted by the patent office on 2018-10-16 for coordinated packet data network change for selected internet protocol traffic offload.
This patent grant is currently assigned to IDAC Holdings, Inc.. The grantee listed for this patent is IDAC HOLDINGS, INC.. Invention is credited to Saad Ahmad, Li-Hsiang Sun.
United States Patent |
10,104,591 |
Ahmad , et al. |
October 16, 2018 |
Coordinated packet data network change for selected internet
protocol traffic offload
Abstract
Coordinated P-GW change for SIPTO may be provided. A WTRU may
send and/or receive one or more flows via a first PDN connection
and via a first P-GW. The WTRU may send an indication to the
network that at least one flow of the first PDN connection is
available for SIPTO. The indication may include one or more SIPTO
preferences. The WTRU may receive a message from a MME. The message
may trigger establishment of a second PDN connection via a second
P-GW. The WTRU may move, while maintaining the first PDN
connection, the at least one flow from the first PDN connection to
the second PDN connection. The WTRU may deactivate the first PDN
connection when the one or more flows have been moved to the second
PDN connection and/or when no information has been received via the
first PDN connection after a predetermined duration.
Inventors: |
Ahmad; Saad (Montreal,
CA), Sun; Li-Hsiang (San Diego, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
IDAC HOLDINGS, INC. |
Wilmington |
DE |
US |
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Assignee: |
IDAC Holdings, Inc.
(Wilmington, DE)
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Family
ID: |
51905415 |
Appl.
No.: |
15/892,964 |
Filed: |
February 9, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180167860 A1 |
Jun 14, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15033313 |
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9930597 |
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PCT/US2014/063259 |
Oct 30, 2014 |
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61897771 |
Oct 30, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
36/125 (20180801); H04W 36/12 (20130101); H04W
76/10 (20180201); H04W 36/22 (20130101); H04W
76/32 (20180201); H04W 76/22 (20180201); H04W
76/38 (20180201); H04W 36/0027 (20130101) |
Current International
Class: |
H04L
12/26 (20060101); H04W 36/22 (20090101); H04W
76/10 (20180101); H04W 36/12 (20090101); H04W
76/38 (20180101); H04W 36/00 (20090101); H04W
76/32 (20180101); H04W 76/22 (20180101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2005-244590 |
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Sep 2005 |
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JP |
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2008-278078 |
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Nov 2008 |
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JP |
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2013-17093 |
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Jan 2013 |
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JP |
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2013-17164 |
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Jan 2013 |
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JP |
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Other References
Cisco: "Selected IP Traffic Offload for LTE at SI", 3GPP Draft;
S2-100771_WAS S2-100493_CISCO_SIP for LTE at SI, 3rd Generation
Partnership Project (3GPP), Mobile Competence Centre ; t Route Des
Lucioles ; F-06921 Sophia-Antipolis Cedex ; France, vol. SA WG2,
no. Shenzhen; Jan. 18, 2010, Jan. 21, 2010 (Jan. 21, 2010). cited
by examiner .
3rd Generation Partnership Project(3GPP), Sp-130417, "New Wid on
Study on Co-Ordinated P-GW Change for SIPTO (FS_CSIPTO)", TSG SA
WG1, 3GPP TSG SA Meeting #61, Porto, Portugal, Sep. 9-11, 2013, 5
pages. cited by applicant .
3rd Generation Partnership Project(3GPP), TD S2-101803, "Procedural
Changes to Support Solution 5--Selected IP Traffic Offload
Solution", Qualcomm Incorporated, Ericsson, ST-Ericsson, Nokia
Siemens Network, Nokia, ZTE, Samsung, NEC, LG Electronics, 3GPP TSG
SA WG2 Meeting #78, San Francisco, Usa, Feb. 22-26, 2010, pp. 1-9.
cited by applicant .
3rd Generation Partnership Project(3GPP), TR 22.828 V0.1.0,
"Technical Specification Group SA Study on Co-ordinated PGW Change
for Selected IP Traffic Offload (CSIPTO) (Release 13)", Nov. 2013,
pp. 1-17. cited by applicant .
3rd Generation Partnership Project(3GPP), TR 23.859 V12.0.1,
"Technical Specification Group Services and System Aspects, Local
IP Access (LIP A) Mobility and Selected Ip Traffic Offload (SIPTO)
at the Local Network (Release 12)", Apr. 2013, pp. 1-68. cited by
applicant .
Taleb et al, "DNS-based Solution for Operator Control of Selected
IP Traffic Offload", IEEE International Conference on
Communications (ICC), Kyoto, Jun. 2011, 5 pages. cited by applicant
.
3rd Generation Partnership Project(3GPP), TD S2-100771, "Selected
IP Traffic Offload for LTE at S1", Cisco, 3GPP TSG SA WG2, Meeting
#77, Shenzhen, China, Jan. 18-22, 2010, 7 pages. cited by
applicant.
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Primary Examiner: Towfighi; Afshawn M
Attorney, Agent or Firm: Condo Roccia Koptiw LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the Continuation of U.S. patent application
Ser. No. 15/033,313, filed Apr. 29, 2016, which was the National
Stage entry under 35 U.S.C. .sctn. 371 of Patent Cooperation Treaty
Application PCT/US2014/063259, filed Oct. 30, 2014, which claims
the benefit of U.S. Provisional Patent Application No. 61/897,771,
filed Oct. 30, 2013, the contents of which are hereby incorporated
by reference herein.
Claims
What is claimed:
1. A method of performing wireless transmit/receive unit (WTRU)
assisted offload, the method comprising: sending a first message
that comprises an indication that offload is allowed for a first
flow of a first connection and that offload is disallowed for at
least a second flow of the first connection; receiving a second
message triggering establishment of a second connection;
establishing the second connection without deactivating the first
connection; moving the first flow from the first connection to the
second connection; and maintaining at least the second flow on the
first connection when the first flow is moved to the second
connection.
2. The method of claim 1, wherein the second message is received
based on a load condition associated with the first connection.
3. The method of claim 1, wherein moving the first flow from the
first connection to the second connection is associated with a
packet filter (PF) or a traffic flow template (TFT).
4. The method of claim 1, wherein the first flow is associated with
a real-time application.
5. The method of claim 1, wherein one or more flows are sent via
the first connection, the method further comprising deactivating
the first connection when the one or more flows have been moved to
the second connection or when no information has been received via
the first connection after a predetermined duration.
6. The method of claim 1, wherein the indication comprises an
offload allowed tag.
7. The method of claim 1, wherein the indication is sent at a
bearer level, an IP flow level, or an application level.
8. The method of claim 7, wherein the indication is sent at the
application level via an application ID indicating an offload
allowed status that corresponds to a running application.
9. The method of claim 7, wherein the indication is sent at the
bearer level and indicates one or more bearers available for
offload.
10. The method of claim 1, wherein the indication is sent when a
running application closes or when a display of the WTRU enters an
idle state.
11. A wireless transmit/receive unit (WTRU) comprising a processor
configured at least in part to: send a first message that comprises
an indication that offload is allowed for a first flow of a first
connection and that offload is disallowed for a second flow of the
first connection; receive a second message that triggers
establishment of a second connection; establish the second
connection without deactivating the first connection; moved the
first flow from the first connection to the second connection; and
maintain at least the second flow on the first connection when the
first flow is moved to the second connection.
12. The WTRU of claim 11, wherein the second message is received
based on a load condition associated with the first connection.
13. The WTRU of claim 11, wherein the first flow is moved to the
second connection via a packet filter (PF) or a traffic flow
template (TFT).
14. The WTRU of claim 11, wherein the indication indicates one or
more offload preferences, and wherein the one or more offload
preferences comprise an indication that the first flow is to be
moved to the second connection prior to deactivating the first
connection.
15. The WTRU of claim 11, wherein one or more flows are sent via
the first connection, the processor further configured to
deactivate the first connection when the one or more flows have
been moved to the second connection or when no information has been
received via the first connection after a predetermined
duration.
16. The WTRU of claim 11, wherein the indication comprises an
offload allowed tag.
17. The WTRU of claim 11, wherein the indication is sent at a
bearer level, an IP flow level, or an application level.
18. The WTRU of claim 17, wherein the indication is sent at the
application level via an application ID that indicates an offload
allowed status that corresponds to a running application.
19. The WTRU of claim 17, wherein the indication is sent at the
bearer level and indicates one or more bearers available for
offload.
Description
BACKGROUND
Networks that utilize small cells (e.g., Home eNodeB devices) are
gaining momentum in the marketplace. Examples of small cells may
include cells that are served by relatively lower power base
stations, for example including relatively lower power evolved Node
B (eNB) devices such as home eNBs (HeNBs), Relay Nodes (RNs),
Remote Radio Heads (RRHs), and/or the like. The small cell base
stations may have a relatively smaller coverage area as compared to
a macro cell. Such small cells are often added to a network to
increase capacity in areas with high levels of user and/or to
provide additional coverage in areas not covered by the macro
network--e.g., both outdoors and/or indoors. Small cells can also
improve network performance and service quality by facilitating the
offloading of traffic from the large macro-cells. Such
heterogeneous networks with large macro-cells in combination with
small cells can provide increased bitrates per unit area.
An offloading technique known as Selected IP Traffic Offload
(SIPTO) may allow an operator to select a packet data network (PDN)
gateway (PDN GW or P-GW) for one or more wireless transmit receive
units (WTRUSs) that may take into account the location of the WTRU.
The WTRU's PDN connection may be torn down and reestablished if the
network realizes it may be advantageous to do so, for example,
based on the location of the WTRU. Such techniques for reselecting
a PDN GW that is closer to the actual location of the WTRU may
facilitate more efficient routing of data within the core network,
thereby more efficiently utilizing network resources. SIPTO may be
used to enable local breakout of traffic from a small cell.
SIPTO may allow an operator to streamline an established PDN
connection by reassigning a new P-GW that may be geographically
closer to the current location of a WTRU. P-GW relocation may imply
a change in IP address, and performing SIPTO may disrupt any
ongoing services. It has been recommended that SIPTO should not be
performed for WTRUs in a connected mode to avoid disrupting ongoing
services. While this recommendation may represent an improvement
compared to blindly performed SIPTO, it fails to address the issue
of smooth P-GW relocation for WTRUs with long-lived and real-time
IP flows, e.g. long conference calls, large file transfers, and the
like.
SUMMARY
SIPTO may be performed to avoid service disruptions due to an IP
address change. A WTRU may send and/or receive one or more flows
via a first PDN connection. The WTRU may send an indication to the
network that at least one flow of the first PDN connection is
available for SIPTO. The indication may indicate one or more other
flows of the first PDN connection for which SIPTO is not allowed.
The first PDN connection may be via a first P-GW. The indication
may include one or more SIPTO preferences. The indication may
include a SIPTO allowed tag. The indication may be sent via a
non-access stratum (NAS) message to a MME in the network. The
indication may be sent at a bearer level, an IP flow level, and/or
an application level. When the indication is sent at the
application level, the indication may include an application ID
indicating a SIPTO allowed status that corresponds to an
application being executed at the WTRU. When the indication is sent
at the bearer level, the indication may indicate one or more
bearers available for SIPTO. The indication may be sent, for
example, when an application being executed at the WTRU is closed
or stopped. As another example, the indication may be sent when a
display of a WTRU enters an idle state.
The WTRU may receive a message from the MME. The message may
trigger establishment of a second PDN connection via a second P-GW.
The WTRU may establish the second PDN connection via the second
P-GW. The WTRU may move, while maintaining the first PDN
connection, the at least one flow for which it was indicated that
SIPTO was allowed from the first PDN connection to the second PDN
connection. The WTRU may deactivate the first PDN connection. For
example, the WTRU may deactivate the first PDN connection when the
one or more flows have been moved to the second PDN connection. As
another example, the WTRU may deactivate the first PDN connection
when no information has been received via the first PDN connection
after a predetermined duration.
A MME in the network may receive, from a WTRU, an indication that
at least one flow of a first PDN connection is available for SIPTO
and/or that one or more other flows may not be moved using SIPTO.
The indication may include one or more SIPTO preferences and may be
received at a bearer level, an IP flow level, or an application
level. When the indication is received at the bearer level, the
indication may indicate one or more bearers available for SIPTO.
When the indication is received at the application level, the
indication may include an application ID indicating a SIPTO allowed
status that corresponds to a running application on the WTRU.
The MME may receive a list of applications from the WTRU. The MME
may determine one or more bearers to offload based on the list of
applications. The MME may determine whether to perform SIPTO for
one or more flows of the first PDN connection. The MME may send a
message, to the WTRU, that triggers establishment of a second PDN
connection via a second P-GW. The message may include a NAS
message. The message may confirm an accuracy of the list of
applications. The message may be a first NAS message. The
indication may be a second NAS message. The second NAS message may
include a SIPTO allowed tag. The MME may perform a serving gateway
(S-GW) relocation. The MME may receive, from an eNodeB, a local
HeNB (LHN) identification (LHN-ID) of the second PDN connection.
The MME may send the LHN-ID of the second PDN connection to the
WTRU. The LHN-ID may include an IP address of a P-GW associated
with the second PDN connection.
The MME may separate an access point name (APN) aggregate maximum
bit-rate (APN-AMBR) into a first APN-AMBR associated with the first
PDN connection and a second APN-AMBR associated with the second PDN
connection. The MME may receive subscription data. The subscription
data may include the APN-AMBR. The MME may determine a modified
first APN-AMBR. The MME may signal the modified first APN-AMBR to
an eNodeB. The MME may send a modified bearer command to a S-GW.
The modified bearer command may identify the modified first
APN-AMBR. The S-GW may enforce the first and second APN-AMBR.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a system diagram of an example communications system in
which one or more disclosed embodiments may be implemented.
FIG. 1B is a system diagram of an example wireless transmit/receive
unit (WTRU) that may be used within the communications system
illustrated in FIG. 1A.
FIG. 1C is a system diagram of an example radio access network and
an example core network that may be used within the communications
system illustrated in FIG. 1A.
FIG. 1D is a system diagram of another example radio access network
and another example core network that may be used within the
communications system illustrated in FIG. 1A.
FIG. 1E is a system diagram of another example radio access network
and another example core network that may be used within the
communications system illustrated in FIG. 1A.
FIG. 2 illustrates an example call flow for a SIP session with
re-invite.
FIGS. 3 and 4 illustrate an example network employing a
make-before-break SIPTO PDN connection.
FIGS. 5 and 6 illustrate an example network employing
make-before-break SIPTO for the case of SIPTO@LN with standalone
LGW.
FIGS. 7 and 8 illustrate an example network employing
make-before-break SIPTO for the case of SIPTO@LN with collocated
LGW.
DETAILED DESCRIPTION
A detailed description of illustrative embodiments will now be
described with reference to the various Figures. Although this
description provides a detailed example of possible
implementations, it should be noted that the details are intended
to be exemplary and in no way limit the scope of the
application.
FIG. 1A is a diagram of an example communications system 100 in
which one or more disclosed embodiments may be implemented. The
communications system 100 may be a multiple access system that
provides content, such as voice, data, video, messaging, broadcast,
etc., to multiple wireless users. The communications system 100 may
enable multiple wireless users to access such content through the
sharing of system resources, including wireless bandwidth. For
example, the communications system 100 may employ one or more
channel access methods, such as code division multiple access
(CDMA), time division multiple access (TDMA), frequency division
multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier
FDMA (SC-FDMA), and the like.
As shown in FIG. 1A, the communications system 100 may include
wireless transmit/receive units (WTRUs) 102a, 102b, 102c, and/or
102d (which generally or collectively may be referred to as WTRU
102), a radio access network (RAN) 103/104/105, a core network
106/107/109, a public switched telephone network (PSTN) 108, the
Internet 110, and other networks 112, though it will be appreciated
that the disclosed embodiments contemplate any number of WTRUs,
base stations, networks, and/or network elements. Each of the WTRUs
102a, 102b, 102c, 102d may be any type of device configured to
operate and/or communicate in a wireless environment. By way of
example, the WTRUs 102a, 102b, 102c, 102d may be configured to
transmit and/or receive wireless signals and may include user
equipment (UE), a mobile station, a fixed or mobile subscriber
unit, a pager, a cellular telephone, a personal digital assistant
(PDA), a smartphone, a laptop, a netbook, a personal computer, a
wireless sensor, consumer electronics, and the like.
The communications system 100 may also include a base station 114a
and a base station 114b. Each of the base stations 114a, 114b may
be any type of device configured to wirelessly interface with at
least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access
to one or more communication networks, such as the core network
106/107/109, the Internet 110, and/or the networks 112. By way of
example, the base stations 114a, 114b may be a base transceiver
station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B,
a site controller, an access point (AP), a wireless router, and the
like. While the base stations 114a, 114b are each depicted as a
single element, it will be appreciated that the base stations 114a,
114b may include any number of interconnected base stations and/or
network elements.
The base station 114a may be part of the RAN 103/104/105, which may
also include other base stations and/or network elements (not
shown), such as a base station controller (BSC), a radio network
controller (RNC), relay nodes, etc. The base station 114a and/or
the base station 114b may be configured to transmit and/or receive
wireless signals within a particular geographic region, which may
be referred to as a cell (not shown). The cell may further be
divided into cell sectors. For example, the cell associated with
the base station 114a may be divided into three sectors. Thus, in
one embodiment, the base station 114a may include three
transceivers, e.g., one for each sector of the cell. In another
embodiment, the base station 114a may employ multiple-input
multiple output (MIMO) technology and, therefore, may utilize
multiple transceivers for each sector of the cell.
The base stations 114a, 114b may communicate with one or more of
the WTRUs 102a, 102b, 102c, 102d over an air interface 115/116/117,
which may be any suitable wireless communication link (e.g., radio
frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible
light, etc.). The air interface 115/116/117 may be established
using any suitable radio access technology (RAT).
More specifically, as noted above, the communications system 100
may be a multiple access system and may employ one or more channel
access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the
like. For example, the base station 114a in the RAN 103/104/105 and
the WTRUs 102a, 102b, 102c may implement a radio technology such as
Universal Mobile Telecommunications System (UMTS) Terrestrial Radio
Access (UTRA), which may establish the air interface 115/116/117
using wideband CDMA (WCDMA). WCDMA may include communication
protocols such as High-Speed Packet Access (HSPA) and/or Evolved
HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access
(HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).
In another embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement a radio technology such as Evolved UMTS
Terrestrial Radio Access (E-UTRA), which may establish the air
interface 115/116/117 using Long Term Evolution (LTE) and/or
LTE-Advanced (LTE-A).
In other embodiments, the base station 114a and the WTRUs 102a,
102b, 102c may implement radio technologies such as IEEE 802.16
(e.g., Worldwide Interoperability for Microwave Access (WiMAX)),
CDMA2000, CDMA2000 1.times., CDMA2000 EV-DO, Interim Standard 2000
(IS-2000), Interim Standard 95 (IS-95), Interim Standard 856
(IS-856), Global System for Mobile communications (GSM), Enhanced
Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the
like.
The base station 114b in FIG. 1A may be a wireless router, Home
Node B, Home eNode B, or access point, for example, and may utilize
any suitable RAT for facilitating wireless connectivity in a
localized area, such as a place of business, a home, a vehicle, a
campus, and the like. In one embodiment, the base station 114b and
the WTRUs 102c, 102d may implement a radio technology such as IEEE
802.11 to establish a wireless local area network (WLAN). In
another embodiment, the base station 114b and the WTRUs 102c, 102d
may implement a radio technology such as IEEE 802.15 to establish a
wireless personal area network (WPAN). In yet another embodiment,
the base station 114b and the WTRUs 102c, 102d may utilize a
cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.)
to establish a picocell or femtocell. As shown in FIG. 1A, the base
station 114b may have a direct connection to the Internet 110.
Thus, the base station 114b may not be required to access the
Internet 110 via the core network 106/107/109.
The RAN 103/104/105 may be in communication with the core network
106/107/109, which may be any type of network configured to provide
voice, data, applications, and/or voice over internet protocol
(VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d.
For example, the core network 106/107/109 may provide call control,
billing services, mobile location-based services, pre-paid calling,
Internet connectivity, video distribution, etc., and/or perform
high-level security functions, such as user authentication.
Although not shown in FIG. 1A, it will be appreciated that the RAN
103/104/105 and/or the core network 106/107/109 may be in direct or
indirect communication with other RANs that employ the same RAT as
the RAN 103/104/105 or a different RAT. For example, in addition to
being connected to the RAN 103/104/105, which may be utilizing an
E-UTRA radio technology, the core network 106/107/109 may also be
in communication with another RAN (not shown) employing a GSM radio
technology.
The core network 106/107/109 may also serve as a gateway for the
WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet
110, and/or other networks 112. The PSTN 108 may include
circuit-switched telephone networks that provide plain old
telephone service (POTS). The Internet 110 may include a global
system of interconnected computer networks and devices that use
common communication protocols, such as the transmission control
protocol (TCP), user datagram protocol (UDP) and the internet
protocol (IP) in the TCP/IP internet protocol suite. The networks
112 may include wired or wireless communications networks owned
and/or operated by other service providers. For example, the
networks 112 may include another core network connected to one or
more RANs, which may employ the same RAT as the RAN 103/104/105 or
a different RAT.
Some or all of the WTRUs 102a, 102b, 102c, 102d in the
communications system 100 may include multi-mode capabilities,
e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple
transceivers for communicating with different wireless networks
over different wireless links. For example, the WTRU 102c shown in
FIG. 1A may be configured to communicate with the base station
114a, which may employ a cellular-based radio technology, and with
the base station 114b, which may employ an IEEE 802 radio
technology.
FIG. 1B is a system diagram of an example WTRU 102. As shown in
FIG. 1B, the WTRU 102 may include a processor 118, a transceiver
120, a transmit/receive element 122, a speaker/microphone 124, a
keypad 126, a display/touchpad 128, non-removable memory 130,
removable memory 132, a power source 134, a global positioning
system (GPS) chipset 136, and other peripherals 138. It will be
appreciated that the WTRU 102 may include any sub-combination of
the foregoing elements while remaining consistent with an
embodiment. Also, embodiments contemplate that the base stations
114a and 114b, and/or the nodes that base stations 114a and 114b
may represent, such as but not limited to transceiver station
(BTS), a Node-B, a site controller, an access point (AP), a home
node-B, an evolved home node-B (eNodeB), a home evolved node-B
(HeNB or HeNodeB), a home evolved node-B gateway, and proxy nodes,
among others, may include some or all of the elements depicted in
FIG. 1B and described herein.
The processor 118 may be a general purpose processor, a special
purpose processor, a conventional processor, a digital signal
processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a
microcontroller, Application Specific Integrated Circuits (ASICs),
Field Programmable Gate Array (FPGAs) circuits, any other type of
integrated circuit (IC), a state machine, and the like. The
processor 118 may perform signal coding, data processing, power
control, input/output processing, and/or any other functionality
that enables the WTRU 102 to operate in a wireless environment. The
processor 118 may be coupled to the transceiver 120, which may be
coupled to the transmit/receive element 122. While FIG. 1B depicts
the processor 118 and the transceiver 120 as separate components,
it will be appreciated that the processor 118 and the transceiver
120 may be integrated together in an electronic package or
chip.
The transmit/receive element 122 may be configured to transmit
signals to, or receive signals from, a base station (e.g., the base
station 114a) over the air interface 115/116/117. For example, in
one embodiment, the transmit/receive element 122 may be an antenna
configured to transmit and/or receive RF signals. In another
embodiment, the transmit/receive element 122 may be an
emitter/detector configured to transmit and/or receive IR, UV, or
visible light signals, for example. In yet another embodiment, the
transmit/receive element 122 may be configured to transmit and
receive both RF and light signals. It will be appreciated that the
transmit/receive element 122 may be configured to transmit and/or
receive any combination of wireless signals.
In addition, although the transmit/receive element 122 is depicted
in FIG. 1B as a single element, the WTRU 102 may include any number
of transmit/receive elements 122. More specifically, the WTRU 102
may employ MIMO technology. Thus, in one embodiment, the WTRU 102
may include two or more transmit/receive elements 122 (e.g.,
multiple antennas) for transmitting and receiving wireless signals
over the air interface 115/116/117.
The transceiver 120 may be configured to modulate the signals that
are to be transmitted by the transmit/receive element 122 and to
demodulate the signals that are received by the transmit/receive
element 122. As noted above, the WTRU 102 may have multi-mode
capabilities. Thus, the transceiver 120 may include multiple
transceivers for enabling the WTRU 102 to communicate via multiple
RATs, such as UTRA and IEEE 802.11, for example.
The processor 118 of the WTRU 102 may be coupled to, and may
receive user input data from, the speaker/microphone 124, the
keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal
display (LCD) display unit or organic light-emitting diode (OLED)
display unit). The processor 118 may also output user data to the
speaker/microphone 124, the keypad 126, and/or the display/touchpad
128. In addition, the processor 118 may access information from,
and store data in, any type of suitable memory, such as the
non-removable memory 130 and/or the removable memory 132. The
non-removable memory 130 may include random-access memory (RAM),
read-only memory (ROM), a hard disk, or any other type of memory
storage device. The removable memory 132 may include a subscriber
identity module (SIM) card, a memory stick, a secure digital (SD)
memory card, and the like. In other embodiments, the processor 118
may access information from, and store data in, memory that is not
physically located on the WTRU 102, such as on a server or a home
computer (not shown).
The processor 118 may receive power from the power source 134, and
may be configured to distribute and/or control the power to the
other components in the WTRU 102. The power source 134 may be any
suitable device for powering the WTRU 102. For example, the power
source 134 may include one or more dry cell batteries (e.g.,
nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride
(NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and
the like.
The processor 118 may also be coupled to the GPS chipset 136, which
may be configured to provide location information (e.g., longitude
and latitude) regarding the current location of the WTRU 102. In
addition to, or in lieu of, the information from the GPS chipset
136, the WTRU 102 may receive location information over the air
interface 115/116/117 from a base station (e.g., base stations
114a, 114b) and/or determine its location based on the timing of
the signals being received from two or more nearby base stations.
It will be appreciated that the WTRU 102 may acquire location
information by way of any suitable location-determination
implementation while remaining consistent with an embodiment.
The processor 118 may further be coupled to other peripherals 138,
which may include one or more software and/or hardware modules that
provide additional features, functionality and/or wired or wireless
connectivity. For example, the peripherals 138 may include an
accelerometer, an e-compass, a satellite transceiver, a digital
camera (for photographs or video), a universal serial bus (USB)
port, a vibration device, a television transceiver, a hands free
headset, a Bluetooth.RTM. module, a frequency modulated (FM) radio
unit, a digital music player, a media player, a video game player
module, an Internet browser, and the like.
FIG. 1C is a system diagram of the RAN 103 and the core network 106
according to an embodiment. As noted above, the RAN 103 may employ
a UTRA radio technology to communicate with the WTRUs 102a, 102b,
102c over the air interface 115. The RAN 103 may also be in
communication with the core network 106. As shown in FIG. 1C, the
RAN 103 may include Node-Bs 140a, 140b, 140c, which may each
include one or more transceivers for communicating with the WTRUs
102a, 102b, 102c over the air interface 115. The Node-Bs 140a,
140b, 140c may each be associated with a particular cell (not
shown) within the RAN 103. The RAN 103 may also include RNCs 142a,
142b. It will be appreciated that the RAN 103 may include any
number of Node-Bs and RNCs while remaining consistent with an
embodiment.
As shown in FIG. 1C, the Node-Bs 140a, 140b may be in communication
with the RNC 142a. Additionally, the Node-B 140c may be in
communication with the RNC 142b. The Node-Bs 140a, 140b, 140c may
communicate with the respective RNCs 142a, 142b via an Iub
interface. The RNCs 142a, 142b may be in communication with one
another via an Iur interface. Each of the RNCs 142a, 142b may be
configured to control the respective Node-Bs 140a, 140b, 140c to
which it is connected. In addition, each of the RNCs 142a, 142b may
be configured to carry out or support other functionality, such as
outer loop power control, load control, admission control, packet
scheduling, handover control, macrodiversity, security functions,
data encryption, and the like.
The core network 106 shown in FIG. 1C may include a media gateway
(MGW) 144, a mobile switching center (MSC) 146, a serving GPRS
support node (SGSN) 148, and/or a gateway GPRS support node (GGSN)
150. While each of the foregoing elements are depicted as part of
the core network 106, it will be appreciated that any one of these
elements may be owned and/or operated by an entity other than the
core network operator.
The RNC 142a in the RAN 103 may be connected to the MSC 146 in the
core network 106 via an IuCS interface. The MSC 146 may be
connected to the MGW 144. The MSC 146 and the MGW 144 may provide
the WTRUs 102a, 102b, 102c with access to circuit-switched
networks, such as the PSTN 108, to facilitate communications
between the WTRUs 102a, 102b, 102c and traditional land-line
communications devices.
The RNC 142a in the RAN 103 may also be connected to the SGSN 148
in the core network 106 via an IuPS interface. The SGSN 148 may be
connected to the GGSN 150. The SGSN 148 and the GGSN 150 may
provide the WTRUs 102a, 102b, 102c with access to packet-switched
networks, such as the Internet 110, to facilitate communications
between and the WTRUs 102a, 102b, 102c and IP-enabled devices.
As noted above, the core network 106 may also be connected to the
networks 112, which may include other wired or wireless networks
that are owned and/or operated by other service providers.
FIG. 1D is a system diagram of the RAN 104 and the core network 107
according to an embodiment. As noted above, the RAN 104 may employ
an E-UTRA radio technology to communicate with the WTRUs 102a,
102b, 102c over the air interface 116. The RAN 104 may also be in
communication with the core network 107.
The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will
be appreciated that the RAN 104 may include any number of eNode-Bs
while remaining consistent with an embodiment. The eNode-Bs 160a,
160b, 160c may each include one or more transceivers for
communicating with the WTRUs 102a, 102b, 102c over the air
interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may
implement MIMO technology. Thus, the eNode-B 160a, for example, may
use multiple antennas to transmit wireless signals to, and receive
wireless signals from, the WTRU 102a.
Each of the eNode-Bs 160a, 160b, 160c may be associated with a
particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the uplink and/or downlink, and the like. As shown in FIG.
1D, the eNode-Bs 160a, 160b, 160c may communicate with one another
over an X2 interface.
The core network 107 shown in FIG. 1D may include a mobility
management gateway (MME) 162, a serving gateway 164, and a packet
data network (PDN) gateway 166. While each of the foregoing
elements are depicted as part of the core network 107, it will be
appreciated that any one of these elements may be owned and/or
operated by an entity other than the core network operator.
The MME 162 may be connected to each of the eNode-Bs 160a, 160b,
160c in the RAN 104 via an S1 interface and may serve as a control
node. For example, the MME 162 may be responsible for
authenticating users of the WTRUs 102a, 102b, 102c, bearer
activation/deactivation, selecting a particular serving gateway
during an initial attach of the WTRUs 102a, 102b, 102c, and the
like. The MME 162 may also provide a control plane function for
switching between the RAN 104 and other RANs (not shown) that
employ other radio technologies, such as GSM or WCDMA.
The serving gateway 164 may be connected to each of the eNode-Bs
160a, 160b, 160c in the RAN 104 via the S1 interface. The serving
gateway 164 may generally route and forward user data packets
to/from the WTRUs 102a, 102b, 102c. The serving gateway 164 may
also perform other functions, such as anchoring user planes during
inter-eNode B handovers, triggering paging when downlink data is
available for the WTRUs 102a, 102b, 102c, managing and storing
contexts of the WTRUs 102a, 102b, 102c, and the like.
The serving gateway 164 may also be connected to the PDN gateway
166, which may provide the WTRUs 102a, 102b, 102c with access to
packet-switched networks, such as the Internet 110, to facilitate
communications between the WTRUs 102a, 102b, 102c and IP-enabled
devices.
The core network 107 may facilitate communications with other
networks. For example, the core network 107 may provide the WTRUs
102a, 102b, 102c with access to circuit-switched networks, such as
the PSTN 108, to facilitate communications between the WTRUs 102a,
102b, 102c and traditional land-line communications devices. For
example, the core network 107 may include, or may communicate with,
an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that
serves as an interface between the core network 107 and the PSTN
108. In addition, the core network 107 may provide the WTRUs 102a,
102b, 102c with access to the networks 112, which may include other
wired or wireless networks that are owned and/or operated by other
service providers.
FIG. 1E is a system diagram of the RAN 105 and the core network 109
according to an embodiment. The RAN 105 may be an access service
network (ASN) that employs IEEE 802.16 radio technology to
communicate with the WTRUs 102a, 102b, 102c over the air interface
117. As will be further discussed below, the communication links
between the different functional entities of the WTRUs 102a, 102b,
102c, the RAN 105, and the core network 109 may be defined as
reference points.
As shown in FIG. 1E, the RAN 105 may include base stations 180a,
180b, 180c, and an ASN gateway 182, though it will be appreciated
that the RAN 105 may include any number of base stations and ASN
gateways while remaining consistent with an embodiment. The base
stations 180a, 180b, 180c may each be associated with a particular
cell (not shown) in the RAN 105 and may each include one or more
transceivers for communicating with the WTRUs 102a, 102b, 102c over
the air interface 117. In one embodiment, the base stations 180a,
180b, 180c may implement MIMO technology. Thus, the base station
180a, for example, may use multiple antennas to transmit wireless
signals to, and receive wireless signals from, the WTRU 102a. The
base stations 180a, 180b, 180c may also provide mobility management
functions, such as handoff triggering, tunnel establishment, radio
resource management, traffic classification, quality of service
(QoS) policy enforcement, and the like. The ASN gateway 182 may
serve as a traffic aggregation point and may be responsible for
paging, caching of subscriber profiles, routing to the core network
109, and the like.
The air interface 117 between the WTRUs 102a, 102b, 102c and the
RAN 105 may be defined as an R1 reference point that implements the
IEEE 802.16 specification. In addition, each of the WTRUs 102a,
102b, 102c may establish a logical interface (not shown) with the
core network 109. The logical interface between the WTRUs 102a,
102b, 102c and the core network 109 may be defined as an R2
reference point, which may be used for authentication,
authorization, IP host configuration management, and/or mobility
management.
The communication link between each of the base stations 180a,
180b, 180c may be defined as an R8 reference point that includes
protocols for facilitating WTRU handovers and the transfer of data
between base stations. The communication link between the base
stations 180a, 180b, 180c and the ASN gateway 182 may be defined as
an R6 reference point. The R6 reference point may include protocols
for facilitating mobility management based on mobility events
associated with each of the WTRUs 102a, 102b, 102c.
As shown in FIG. 1E, the RAN 105 may be connected to the core
network 109. The communication link between the RAN 105 and the
core network 109 may defined as an R3 reference point that includes
protocols for facilitating data transfer and mobility management
capabilities, for example. The core network 109 may include a
mobile IP home agent (MIP-HA) 184, an authentication,
authorization, accounting (AAA) server 186, and a gateway 188.
While each of the foregoing elements are depicted as part of the
core network 109, it will be appreciated that any one of these
elements may be owned and/or operated by an entity other than the
core network operator.
The MIP-HA may be responsible for IP address management, and may
enable the WTRUs 102a, 102b, 102c to roam between different ASNs
and/or different core networks. The MIP-HA 184 may provide the
WTRUs 102a, 102b, 102c with access to packet-switched networks,
such as the Internet 110, to facilitate communications between the
WTRUs 102a, 102b, 102c and IP-enabled devices. The AAA server 186
may be responsible for user authentication and for supporting user
services. The gateway 188 may facilitate interworking with other
networks. For example, the gateway 188 may provide the WTRUs 102a,
102b, 102c with access to circuit-switched networks, such as the
PSTN 108, to facilitate communications between the WTRUs 102a,
102b, 102c and traditional land-line communications devices. In
addition, the gateway 188 may provide the WTRUs 102a, 102b, 102c
with access to the networks 112, which may include other wired or
wireless networks that are owned and/or operated by other service
providers.
Although not shown in FIG. 1E, it will be appreciated that the RAN
105 may be connected to other ASNs and the core network 109 may be
connected to other core networks. The communication link between
the RAN 105 the other ASNs may be defined as an R4 reference point,
which may include protocols for coordinating the mobility of the
WTRUs 102a, 102b, 102c between the RAN 105 and the other ASNs. The
communication link between the core network 109 and the other core
networks may be defined as an R5 reference, which may include
protocols for facilitating interworking between home core networks
and visited core networks.
With SIPTO at a Local Network (SIPTO@LN), a P-GW (e.g., alias Local
Gateway) may be relocated (e.g., moved even further) toward a
network edge and may be collocated with an eNodeB. SIPTO@LN may
lead to a relatively flat architecture (e.g., IP traffic can be
broken out close to the network edge). With SIPTO@LN, frequency of
service disruption due to SIPTO may increase (e.g., due to smaller
coverage of the Local Gateway).
Service disruption due to an IP address change may include one or
more effects on short-lived and/or long-lived/real-time flows. For
example, for short-lived flows (e.g., web browsing) the service
disruption due to a SIPTO-induced IP address change may be
relatively mild. In some case, a user executing a relatively
short-lived flow may not notice anything when SIPTO is performed
within the network. In some examples, although the short-lived flow
user may notice a slight disruption, the service disruption may be
slight. For example, the user may interact (e.g., briefly interact)
with a user interface, for example, by selecting a web page link
after a "network connection lost" error, selecting a refresh icon,
and/or the like. However, for long-lived and real-time flows, the
effect of service disruption due to SIPTO may be detrimental. For
example, a user may be ejected from a conference call and may have
to redial a bridge number, enter a password, etc. VPN traffic may
be similarly detrimentally affected by service disruption due to IP
address change caused by SIPTO.
The WTRU may be able to identify a presence of long-lived and/or
real-time flows. For example, the WTRU may inspect the flows that
have been established to identify which flows are relatively short
lived flows and which a relatively long lived flows. The WTRU may
identify the short lived flows as flows that will result in minimal
service disruption for the user if SIPTO is performed for the flow.
The WTRU may identify the long lived flows as flows that will
result in a relatively large service disruption for the user if
SIPTO is performed for the flow. The WTRU may advise the network as
to whether SIPTO may be performed (e.g., without much or any
disruption), based on the presence of long-lived and/or real-time
flows, for example on a per-flow basis.
In order to avoid service disruptions for long-lived flows, the
WTRU may be configured to proactively create a new PDN connection
for a long lived flow prior to breaking down the existing PDN
connection for the long lived flow. Once the new PDN connection is
established, the WTRU may remove the old PDN connection for the
flow. As a result of creating the new PDN connection prior to
breaking down the old PDN connection, the WTRU may ensure that the
service disruption due the SIPTO/PDN GW change is minimized for
long lived and/or real-time flows. For non-long lived flows and/or
non-real-time flows (e.g., short lived flows such as those
associated with internet browsing, a chat sessions, etc.), the WTRU
may indicate to the network that SIPTO/PDN GW change can be
performed without setting up the new connection prior to moving the
old connection. The WTRU may support one or more flows via a first
IP address with a first PDN connection. For supporting
applications, the WTRU may proactively move one or more long-lived
and/or real-time flows from the first IP address (e.g., an existing
IP address) to a second IP address (e.g., a new IP address). The
second IP address may include a new PDN connection. The WTRU may
move the one or more long-lived and/or real-time flows to the
second IP address via a second PDN connection before the first IP
address (e.g., first PDN connection) is removed. For example, a
multimedia telephony service (MMTel) set of applications and/or
other applications may be capable of proactively moving one or more
long-lived and/or real-time flows as described herein. An IMS
application may allow a change of media transport addresses for an
ongoing session using IMS service continuity mechanisms.
A network may consider an end-user's expectation regarding local
P-GW change in case of SIPTO use. For example, the network may
consider the end-user's expectation based on one or more end-user
preferences, to benefit from the WTRU's knowledge of the flow type
of an established IP flow, and/or the like.
A WTRU may send one or more preferences to the network. The WTRU
may send the one or more preferences to the network to ensure that
a seamless handover takes place when moving flows from non-SIPTO to
SIPTO PDN connections and vice versa. Various network nodes, such
as HSS (e.g., including subscription parameters), MME, and/or WTRU
may take actions to ensure the seamless handover. As an example,
the preference information may indicate whether for a given flow a
new PDN connection associated with a new P-GW is to be established
prior to deactivating the an old PDN connection associated with a
previous P-GW when performing SIPTO for the flow (e.g., for a
long-lived and/or real-time flow). The preference information for
another flow may indicate that the flow can be moved to a new PDN
connection associated with a new P-GW without having to set up the
new PDN connection in advance (e.g., for short-lived and/or
non-real-time/best effort flows). Thus, a make-before-break scheme
for the PDN connection may be used for performing SIPTO for
long-lived and/or real-time flows, and short lived and/or
non-real-time flows may be associated with a SIPTO scheme where the
old PDN connection is deactivated at substantially the same time as
the new PDN connection is activated (e.g., a break while make or
break before make scheme).
There may be a conflict between a network wanting to offload
certain flows or PDN connections to SIPTO@LN and a WTRU wanting to
keep an original PDN connection, for example, for service
continuity or other reasons. The network and/or WTRU may handle or
resolve the conflict.
A 3GPP network may use one or more subscription parameters (e.g.,
subscription information) to determine whether a WTRU supports
WTRU-assisted SIPTO and/or coordinated change of P-GW. The one or
more subscription parameters may be used because one or more WTRUs
in a system may not support WTRU-assisted SIPTO and/or coordinated
change of P-GW. The one or more subscription parameters may be used
because one or more WTRUs in the system may not subscribe to
WTRU-assisted SIPTO and/or coordinated change of P-GW when signing
up with an operator. The one or more subscription parameters may
specify whether the user's or WTRU's input is used to decide
whether the traffic is subject to offloading between 3GPP and
non-3GPP access.
The subscription information may specify what type of traffic may
be subject to offloading. For example, traffic with a specific
quality of service (QoS) or QoS class identifier (QCI), application
type, APN, subscriber profile ID (SPID), and/or the like may be
subject to offloading. As another example, all traffic except voice
traffic may be subject to offloading. As another example, voice
calls except for emergency voice calls may be subject to
offloading. The subscription information may specify which bearers,
IP flows, and/or PDN may be subject to offloading. The subscription
information may specify that background traffic may be subject to
offloading. The subscription information may specify that a default
bearer (e.g., only the default bearer) is subject to offloading.
The subscription information may specify that one or more dedicated
bearers (e.g., only the dedicated bearers) are subject to
offloading.
The subscription information may specify whether the network may
consider (e.g., may always have to take into consideration) an
indication and/or an assistance information sent by the WTRU for a
coordinated P-GW change. The subscription information may specify
whether offloading may be applicable to a particular cell, e.g., a
CSG cell, or a local network with a specific local network
identity, or a tracking area, etc. The subscription information may
specify a list of applications and/or application IDs. The list of
applications and/or application IDs may include applications that
may benefit from a seamless transition to a local network and/or
applications that may use input from a user or WTRU or a preference
about whether the bearer containing such application data may be
moved to SIPTO@LN.
Upon registration to the network, a HSS may provide subscription
information to a MME and/or a node that is fetching the WTRU's
subscription information (e.g., SGSN, MSC, etc.). The MME (e.g., or
a node with similar functionality, such as the SGSN) may send the
subscription information to one or more core network nodes, such as
the Serving Gateway (S-GW) and/or the Packet Data Network (PDN)
Gateway (PDN GW or P-GW).
The subscription information may be forwarded from a first MME to a
second MME during an inter-MME handover. The source may include the
subscription information as part of the transferred WTRU context.
The source MME/SGSN may include the subscription information when
handing over to another system node such as an SGSN/MME,
respectively.
The subscription information may be provided to the WTRU, for
example, via OMA DM, ANDSF, SMS, etc. The WTRU may provide the
subscription information to the eNB. The eNB may use the
subscription information to determine whether to offload traffic.
The eNB may determine whether to offload traffic based on the
subscription information and/or a WTRU preference.
A WTRU may provide capability information to a network and/or a
MME. The WTRU may provide the capability information to the network
and/or the MME via a capability information element (IE). The
capability IE may inform the MME that the WTRU may be able to send
or capable of sending one or more flow preferences to decide which
flows, bearers, and/or PDN connections may be offloaded to
SIPTO@LN. The MME may use the capability information received from
a HSS and/or the capability IE to determine whether to perform
network imitated SIPTO and/or WTRU-assisted SIPTO offload.
When a WTRU enters a local network or a cell or in coverage of an
eNB or a HeNB where SIPTO offload may be possible, the WTRU may be
aware that the local network, the cell, and/or the eNB supports
SIPTO offload. The WTRU may determine whether to send one or more
preferences to the local network, the cell, and/or the eNB. The one
or more preferences may include one or more SIPTO preferences. The
WTRU may send the one or more preferences via an indication. The
one or more preferences and/or the indication that may be sent to
the network are disclosed herein. The one or more preferences may
be sent to the MME via a NAS message (e.g., a NAS message that may
be defined for the purpose of sending one or more SIPTO preferences
to the MME).
The WTRU may be aware of whether an eNB or a cell supports SIPTO or
is connected to an L-GW. When the WTRU determines that the eNB or
the cell supports SIPTO or determines that the eNB or the cell is
connected to a L-GW, the network or the MME may send a message to
the WTRU. The message may indicate that one or more flows of the
WTRU's traffic may be subject to SIPTO@LN and/or SIPTO offloading.
The WTRU may send one or more preferences (e.g., SIPTO preferences)
about one or more flows and/or an application that it wants to be
offloaded to the SIPTO@LN PDN connection.
The WTRU may send preference information to the MME (e.g., for
coordinated P-GW change for SIPTO). The preference information may
include an indication that at least one flow is available for
SIPTO. The preference information may include one or more of the
following. The WTRU may send a tag or an IE that indicates whether
SIPTO is allowed or disallowed on one or more PDN connections
(e.g., that the WTRU may have at a given time when it moves to the
local network). For example, if the WTRU has two PDN connections
(e.g., a first PDN connection and a second PDN connection) and the
WTRU only wants one of the two PDN connections to be offloaded, the
WTRU may tag one of the two PDN connections as SIPTO allowed and
may tag the other PDN connection as SIPTO not allowed. The WTRU may
indicate that the at least one flow available for SIPTO is on the
first PDN connection. The tag may be sent via a NAS message to the
MME. The NAS message may be sent to the MME that corresponds to an
IP address and/or an identity of one or more PDN connections that
the WTRU may have at a given time.
The WTRU may send preference information at a finer granularity
than a flow. For example, the preference information may be sent at
the bearer level, at the IP flow level, and/or at the application
level. When the preference information is sent at the bearer level,
the WTRU may specify a bearer that can be offloaded to the local
network. When the preference information is sent at the IP flow
level, the WTRU may specify an IP flow or flows that can be
offloaded to the local network. When the preference information is
sent at the application level, the WTRU may send one or more
application IDs to the MME with a corresponding SIPTO status (e.g.,
SIPTO allowed or SIPTO disallowed) for each application running on
the WTRU.
The MME may send an indication that a PDN connection is subject
offloading. When the MME indicates that the PDN connection is
subject to offloading, the WTRU may send (e.g., respond with) an
indication that it does not want to offload and/or may inform the
network when it is ready to offload. For example, the WTRU may send
the indication that it does not want to offload, when a WTRU has
ongoing traffic that it does not want to disrupt, such as a voice
call or a video chat. When the ongoing data session is finished,
the WTRU may send an indication that it is ready for SIPTO offload
and/or that the network can proceed with SIPTO.
A WTRU may reject a network request for SIPTO. The WTRU may reject
the network request for SIPTO, when a user or the WTRU knows that
the SIPTO offload may affect a quality of service and/or a quality
of experience for the user.
When the WTRU is in the local network and/or under the coverage of
an eNB that supports SIPTO, the WTRU may send an indication to
start the SIPTO offload at a next time when the WTRU goes from
connected to idle. When the network receives the indication, the
network may offload one or more flows to SIPTO@LN when the WTRU
moves to idle mode.
The WTRU may send the indication to the network that it may start
the SIPTO offload based on one or more of the following triggers.
For example, the WTRU may send the indication when the WTRU closes
a certain application. The WTRU may not want to perform SIPTO when
a certain application is running on the WTRU. The WTRU may send the
indication (e.g., a start SIPTO indication) when the certain
application is closed down. When an application is started and the
WTRU is in an area where SIPTO is supported, the WTRU may send an
indication to the network to start SIPTO offload. The WTRU may also
send the indication to start SIPTO offload when a display screen of
the WTRU (e.g., smartphone screen) goes to rest (e.g., when the
WTRU locks or the screen goes blank because of inactivity). There
may be an interaction between the operating system of the phone and
the 3GPP protocol stack such that when the screen goes blank, the
3GPP protocol stack may be notified, which in turn may send the
indication to the MME, via a NAS message, that one or more flows
are ready for SIPTO offload.
When the WTRU sends preference information for the coordinated P-GW
change for SIPTO to the network (e.g., MME), the MME may determine
to offload some or all of its traffic to the local network via
SIPTO offload based on the preference information. The MME may take
one or more actions to ensure a seamless SIPTO handover. For
example, the MME may decide not to offload traffic to SIPTO based
on the WTRU preference information. The WTRU may retain an existing
(e.g., the original) PDN connection and/or bearer through the macro
network PDN-GW.
When a MME receives an application ID, a flow identification,
and/or other information about a flow be capable of SIPTO
offloading, the MME may determine to offload the SIPTO capable flow
based on the WTRU preference information. For example, one or more
SIPTO capable flows may be on one or more PDN connections and/or
one or more bearers. The MME may move the one or more flows between
one or more PDN connections. The MME may move the one or more
flows, by establishing a SIPTO@LN PDN connection or sending a
message asking the WTRU to establish (e.g., initiate) a SIPTO@LN
PDN connection for a flow (e.g., every flow) moved to a local
PDN-GW. For example, if the MME wants to move two flows from
different macro PDN connections, the MME may request that the WTRU
establish two SIPTO@LN PDN connections. The MME may request that
the WTRU and move the two flows (e.g., SIPTO capable flows) to the
two PDN connections (e.g., if different flows belong to PDN
connections for different APNs). The MME may request the WTRU to
establish only one SIPTO@LN and move the SIPTO capable flows to
that local network PDN connection (e.g., if the flows from
different PDN connections belong to the same APN or in some other
scenarios). The MME may send or install one or more traffic filters
to change the direction of one or more flows from a macro network
PDN connection to a SIPTO@LN. The one or more traffic filters may
include one or more Traffic Flow Templates (TFTs) and/or one or
more Packet Filters (PF). The one or more traffic filters may
direct the SIPTO capable traffic from the WTRU to the L-GW in the
local network.
The WTRU may send a list of applications to the MME while it is
attached to the system. When the MME is about to perform SIPTO, The
MME may confirm with the WTRU whether the WTRU is running the same
applications in the list of applications. The MME may send a NAS
message to the WTRU to check what applications are running. The MME
may determine which bearers to offload and/or whether to perform
the SIPTO offload based on the applications running on the
WTRU.
When the WTRU moves into a local network, the MME may know that a
SIPTO@LN offload may not be possible because when the WTRU moved
into the local network, the MME may have performed a S-GW
relocation without mobility to the S-GW in the local network. The
S-GW in the local network may be collocated with L-GW. One or more
of the WTRU's PDN connections and/or EPS bearers may go through the
S-GW in the local network. The one or more PDN connections and/or
EPS bearers may go through the S-GW in the local network to prepare
for when the WTRU is ready to perform SIPTO offload as the SIPTO
PDN connection may go through the S-GW in the local network.
A WTRU may proactively move one or more flows (e.g., long-lived
and/or real-time flows) from a first IP address to a second IP
address (e.g., on a new PDN connection) before the first IP address
(e.g., old PDN connection) may be removed. For example, a WTRU with
an IMS session may continue to receive or transmit voice or video
media with the first IP address while it is setting up a second IP
address via a second PDN connection and/or performing SIP
re-invitation to the second IP address. The WTRU may (e.g.,
simultaneously) have multiple PDN connections of the same APN, but
to different PGWs (e.g., to continue to receive or transmit voice
or video media with the first IP address while setting up the
second IP address).
FIG. 2 illustrates an example call flow 200 for a SIP session with
re-invite. A first WTRU 202 may establish a connection with (e.g.,
invite) a second WTRU 206. The connection may be established
through a proxy 204. At some point during the connection, the
second WTRU 206 may change an IP address 208. The change in IP
address 208 interrupts (e.g., breaks) the connection between the
first WTRU 202 and the second WTRU 206. The second WTRU 206 must
re-establish the connection with (e.g., re-invite) the first WTRU
202.
A WTRU may be triggered to establish (e.g., create) a PDN
connection for SIPTO via a NAS message. The NAS message may include
a PDN deactivation message with ESM cause "reactivation requested."
Establishing a PDN connection in response to a PDN deactivation
message may be described as break-before-make in nature. A trigger
(e.g., from the network) may be used to inform the WTRU to perform
a PDN connectivity request without deactivating the existing PDN
connection. For example, a message may be sent from the MME to the
WTRU for establishing a PDN connection of a given APN. The message
may be sent via a NAS ESM message. The WTRU may send an indication,
to the MME, that at least one flow of a first PDN connection is
available for SIPTO. The MME may send the message after receiving
the indication from the WTRU that the at least one flow of the
first PDN connection is available for SIPTO and the network decides
to perform SIPTO. The message may be triggered by WTRU mobility.
For example, the message may be sent when the WTRU moves out of a
first LHN area to a second LHN area.
When the WTRU has moved the traffic from a first PDN connection to
a second PDN connection, if the WTRU has not received any packets
from the first PDN connection for a period of time, it may request
the deactivation of the first PDN connection.
FIGS. 3 and 4 illustrate an example network 300 employing a
make-before-break SIPTO PDN connection. As shown in FIG. 3, a WTRU
304 may have a first PDN connection 312 (e.g., an existing PDN
connection) with a first P-GW 306. The first PDN connection 312 may
be via a first L-GW or a first eNodeB 318 and a S-GW 310. One or
more flows may be sent via the first PDN connection 312. An MME 302
may send a message 314 to the WTRU 304. The message 314 may trigger
the WTRU to establish (e.g., to create) a second PDN connection 316
(e.g., a new PDN connection) with a second P-GW 308. The WTRU 304
may establish the second PDN connection 316. The WTRU 304 may
establish the second PDN connection 316 without deactivating the
first PDN connection 312. The MME 302 may send the message 314 to
the WTRU 304 based on a trigger condition disclosed herein, a load
condition of the first P-GW 306 of the first PDN connection 312,
and/or by a location (e.g., an anticipated location) of the WTRU
304 where a second P-GW 308 may be closer to the WTRU's point of
attachment. The WTRU 304 may perform a PDN connectivity request.
The MME 302 may provide the IP address of the second P-GW 308 to
the S-GW 310. The WTRU 304 may move one or more flows from the
first PDN connection 312 to the second PDN connection 316. The WTRU
304 may stop transmitting on the first PDN connection 312.
As shown in FIG. 4, the WTRU 304 may deactivate the first PDN
connection 312 when it has completed moving one or more flows
(e.g., all the existing flows) to the second PDN connection 316
and/or when no information (e.g., data) has been received via the
first PDN connection 312 after a predetermined duration.
While FIGS. 3 and 4 illustrate the WTRU 304 moving from the first
L-GW or first eNodeB 318 to a second L-GW or second eNodeB 320, the
disclosed subject matter may also be applicable when the WTRU 304
remains connected to the first eNodeB 318 or cell.
FIGS. 5 and 6 illustrate an example network 500 employing
make-before-break SIPTO for the case of SIPTO@LN with a standalone
L-GW. The standalone L-GW may be a first L-GW 514. SIPTO@LN may
assume that a target S-GW selected during the handover may have
connectivity to the first L-GW 514. SIPTO may use the connectivity
to the first L-GW 514 for deactivation after a mobility event or a
possible S-GW relocation. Given this assumption, deactivation of a
first PDN connection 518 may be deferred until sometime after
handover to a different LHN area or a macro cell.
A make-before-break SIPTO procedure in the case of SIPTO@LN may
include an MME 502 sending a message 522 to a WTRU 504. The message
522 may trigger the WTRU 504 to establish (e.g., to create) a
second PDN connection 520 with a second P-GW 506. The WTRU 504 may
establish the second PDN connection 520 without deactivating the
first PDN connection 518. For example, the message 522 may be sent
by the MME 502 when the WTRU 504 moves to a different LHN area, or
to a different macro cell. The WTRU 504 may perform a PDN
connectivity request. The MME 502 may provide the IP address of the
second P-GW 506 to a second S-GW 508. The WTRU 504 may move one or
more flows from the first PDN connection 518 to the second PDN
connection 520. The WTRU 504 may stop transmitting on the first PDN
connection 518.
As shown in FIG. 6, the WTRU 504 may deactivate the first PDN
connection 518 when it has completed moving one or more flows
(e.g., all the existing flows) to the second PDN connection 520
and/or when no information (e.g., data) has been received via the
first PDN connection 518 after a predetermined duration. The MME
502 may perform an MME-initiated S-GW relocation from a first S-GW
510 to a second S-GW 508, if the S-GW has not been relocated to the
S-GW 508 during the mobility procedure.
The MME 502 may send the message 522 to the WTRU 504 and the WTRU
504 PDN connectivity request may be performed before the WTRU 504
moves out of a first LHN area (e.g., served by L-GW 514). For
example, the MME 502 may send the message 522 if the MME 502 knows
a LHN-ID for a second LHN area of which the WTRU 504 has not yet
moved into. The second LH area may be associated with the second
PDN connection 520. The LHN-ID may be provided by a source eNB to
the MME 502. The MME may send the LHN-ID of the second PDN
connection 520 to the WTRU 504. The LHN-ID may include an IP
address of a P-GW associated with the second PDN connection
520.
FIGS. 7 and 8 illustrate an example network 700 employing
make-before-break SIPTO for the case of SIPTO@LN with a first L-GW
714 collocated with a first P-GW 710. SIPTO@LN may assume that a
target S-GW 708 selected during the handover may have connectivity
to the first L-GW 714. SIPTO may use the connectivity to the first
L-GW 714 for deactivation after a mobility event or possible S-GW
relocation. Given this assumption, deactivation of a first PDN
connection 712 may be deferred until sometime after handover to a
different HeNB or a macro cell.
A make-before-break SIPTO in the case of SIPTO@LN may include an
MME 702 sending a message 720 to a WTRU 704. The message 720 may
trigger the WTRU 704 to establish (e.g., to create) a second PDN
connection 718 with a second P-GW 706. The WTRU 704 may establish
the second PDN connection 718 without deactivating the first PDN
connection 712. For example, the message 720 may be sent by the MME
702 when the WTRU 704 moves to a different HeNB or macro cell. The
WTRU 704 may perform a PDN connectivity request. The MME 702 may
provide the IP address of the second P-GW 706 to the S-GW 708. The
WTRU 704 may move one or more flows from the first PDN connection
712 to the second PDN connection 718. The WTRU 704 may stop
transmitting on the first PDN connection 712.
As shown in FIG. 8, The WTRU 704 may deactivate the first PDN
connection 712 when the WTRU 704 has completed moving one or more
flows (e.g., all the existing flows) to the second PDN connection
718 and/or when no information (e.g., data) has been received via
the first PDN connection 712 after a predetermined duration.
A SIPTO bearer context may be transferred between MMEs when the
WTRU performs TAU from idle mode. Transfer of the SIPTO bearer
context may be performed via an indication that may identify the
SIPTO bearer. The indication may be used by a target LGW to perform
APN-AMBR policing, as described herein.
In an example EPS architecture, for the same APN there may be a
P-GW (e.g., only one P-GW). The P-GW may enforce APN-AMBR. An APN
may have two P-GWs, which may make APN-AMBR policing difficult.
For SIPTO above RAN, the S-GW 708 may perform APN-AMBR monitoring.
The S-GW 708 may know the APN-AMBR and information relating to
which bearer or bearers belong to the APN.
For SIPTO@LN, APN-AMBR monitoring may be located at a LGW (e.g.,
either collocated with SGW or eNB). The LGW may already perform
APN-AMBR monitoring of a first PDN connection 712. A first APN-AMBR
of the first PDN connection 712 may be summed with a second
APN-AMBR of a second (e.g., a new) PDN connection 718. The LGW may
meter the second PDN connection 718. The sum of the first APN-AMBR
and the second APN-AMBR may be policed.
For a collocated LGW with an eNB, the eNB may not know which bearer
belongs to the first SIPTO PDN connection 712. The MME 702 may
signal this bearer identity to a target eNB.
The MME 702 may separate the APN-AMBR into components that may be
designated, for example, as a first APN-AMBR and a second APN-AMBR.
For example, APN-AMBR=the first APN-AMBR+the second APN-AMBR. The
MME 702 may receive subscription data. The subscription data may
include the APN-AMBR. The MME 702 may determine a modified first
APN-AMBR. The MME 702 may modify the APN-AMBR to the first APN-AMBR
for the first PDN connection 712 (e.g., before the WTRU 704
performs a PDN connectivity request). The MME 702 may signal the
modified first APN-AMBR to an eNodeB. The MME 702 may send a
modified bearer command to a s S-GW 708. The modified bearer
command may identify the modified first APN-AMBR. The MME 702 may
modify the second APN-AMBR-to APN-AMBR for the second PDN
connection 718 (e.g., after the WTRU 704 deactivates the second PDN
connection 718).
The processes and instrumentalities described herein may apply in
any combination, may apply to other wireless technology, and for
other services.
A WTRU may refer to an identity of the physical device, or to the
user's identity such as subscription related identities, e.g.,
MSISDN, SIP URI, etc. WTRU may refer to application-based
identities, e.g., user names that may be used per application.
The processes described above may be implemented in a computer
program, software, and/or firmware incorporated in a
computer-readable medium for execution by a computer and/or
processor. Examples of computer-readable media include, but are not
limited to, electronic signals (transmitted over wired and/or
wireless connections) and/or computer-readable storage media.
Examples of computer-readable storage media include, but are not
limited to, a read only memory (ROM), a random access memory (RAM),
a register, cache memory, semiconductor memory devices, magnetic
media such as, but not limited to, internal hard disks and
removable disks, magneto-optical media, and/or optical media such
as CD-ROM disks, and/or digital versatile disks (DVDs). A processor
in association with software may be used to implement a radio
frequency transceiver for use in a WTRU, UE, terminal, base
station, RNC, and/or any host computer.
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